L-2-OXOTHIAZOLIDINE-4-CARBOXYLIC ACID (PROCYSTEINE) INHIBITS EXPRESSION OF THE HUMAN-IMMUNODEFICIENCY-VIRUS AND EXPRESSION OF THE INTERLEUKIN-2 RECEPTOR-ALPHA CHAIN

These studies were undertaken to examine the in vitro effects of the c ysteine pro- drug L-2-oxothiazolidine-4-carboxylic acid (Procysteine) on human immunodeficiency virus expression. Procysteine inhibited HIV expression in human peripheral blood mononuclear cells as detected by measurement of supernatant core antigen. In transient transfection ass ays, Procysteine inhibited gene expression controlled by the HIV-1 pro moter in activated Jurkat cells but not in resting Jurkat cells. Gel-s hift assays showed that Procysteine inhibited NF-kappa B DNA binding a ctivity in nuclear extracts. Procysteine did not affect the production of interleukin-2 by peripheral blood mononuclear cells of healthy HIV -seronegative subjects, as measured by bioassay but it decreased the d ensity of cell-surface interleukin-2 receptors detected by flow cytome try after stimulation with phytohemagglutinin (PHA). Thus, Procysteine inhibits HIV expression, HIV promoter activity, and NF-kappa B bindin g activity in vitro. Procysteine does not affect interleukin-2 product ion but inhibits interleukin-2 receptor expression in PHA-stimulated p eripheral blood mononuclear cells.